Polyurethane Dispersions Research Articles

BASF, Huntsman in polyurethane ventures

BASF and Japan’s Sanyo Chemical have agreed to jointly develop and produce polyurethane dispersions. The collaboration will cut the time it takes for the partners to develop new products, BASF says. Meanwhile, Huntsman and KPX Chemical, a South Korean producer of polyols, are creating a joint venture company, KPX Huntsman Polyurethanes Automotive, to supply polyurethane to automotive firms in South Korea.

Continuous Production of Water-Based UV-Curable Polyurethane Dispersions Using Static Mixers and a Rotor-Stator Mixer.

UV-curable polyurethane dispersions (UV-PUDs) have applications in coatings for a variety of materials. Historically, the neutralization and dispersion steps of the UV-PUD production process have been performed in batch. However, continuous processing might reduce capital and operating costs, improve the dispersion characteristics, and facilitate scale-up. Static mixers and inline high-shear mixers are able to provide the necessary shear forces to obtain miniemulsions. The production of a UV-PUD is therefore studied in a continuous setup, whereby the neutralization step is performed in static mixers and the dispersion step is performed either in static mixers or in a high-shear mixer. The influence of the prepolymer temperature, mixing energy, and feed flow rate on the particle size and stability of the UV-PUD particles in water is explored. The results show that the neutralization step is mixing-sensitive, and the temperature of the neutralized prepolymer influences the particle size in the dispersion process. The amount of shear force applied during the dispersion step has a limited effect on the particle size. UV-PU dispersions with an average particle size below 80 nm and PDI below 0.1 are obtained with static mixers or in an inline rotor-stator mixer, at flow rates of 5.2 and 7.2 L/h, respectively. This research demonstrates that continuous processing using static mixers and high-shear mixing is a viable option for the neutralization and dispersion of UV-PUDs.

UV-Protected Polyurethane/f-Oil Fly Ash-CeO2 Coating: Effect of Pre-Mixing f-Oil Fly Ash-CeO2 with Monomers.

A series of UV-protected coatings were prepared using cerium-oxide-functionalized oil fly ash (f-OFA-CeO2) in waterborne polyurethane (WBPU) dispersions. Three monomers, namely, poly(tetramethyleneoxide glycol) (PTMG), polydimethylsiloxane-hydroxy terminated (PDMS) and 4,4-dicyclohexylmethane diisocyanate (H12MDI), were used to pre-mix with f-OFA-CeO2 separately, followed by the synthesis of WBPU/f-OFA-CeO2 dispersions. The f-OFA-CeO2 distribution and enrichment into any part (top/bottom/bulk) of the coating was strongly affected by the pre-mixing of f-OFA-CeO2. The f-OFA-CeO2 was densely distributed in the top, bottom and bulk when the f-OFA-CeO2 was pre-mixed with PDMS, H12MDI and PTMG, respectively. Only an f-OFA-CeO2-enriched top surface showed excellent UV protection. The lowest UV-degraded exposed coating was found when the top surface of the coating was f-OFA-CeO2-enriched.

Synthesis of novel curcumin-based aqueous polyurethane dispersions for medical textile diligences with potential of antibacterial activities

Synthesis of novel curcumin-based aqueous polyurethane dispersions for medical textile diligences with potential of antibacterial activities

Improved tear resistance by low environmental impact coupling of plasma reactive and additive treatment of a TPU/PET coated fabric

An environmentally friendly approach, which consists in coupling a dielectric barrier discharge (DBD) based atmospheric plasma treatment with a coating of an aqueous phase polyurethane dispersion (PUD) containing blocked polyisocyanates, is proposed to improve the adhesion of a thermoplastic polyurethane (TPU) film onto a poly-(ethylene terephthalate) (PET) textile fabric. In this study, a screening digital design of experiment plan (DOE) was developed to determine the influence of process parameters on the adhesion between film and fabric and to evaluate the best possible adhesion value. The process parameters considered are: the dielectric barrier discharge power, the speed of the fabric undergoing the treatment, the concentration of polyisocyanates (NCO) in the PUD and the air gap. The adhesion was measured by a peeling test and further scanning electron microscope observations were carried out. Results showed that an increase of both the processing power and the NCO content in PUD, as well as the decrease in the DBD speed, had a positive effect on the adhesion. In addition, X-ray photoelectron spectroscopy and contact angle measurements demonstrated an increase in the oxygen/carbon atomic percentage ratio between the reference fabric and the treated fabric. Thus, the calibrated oxidation of the PET treated with DBD plasma treatment leads to a greater chemical and physical interaction with the TPU film, which results in better film-fabric adhesion.

Preparation and properties of rosin-based cationic waterborne polyurethane dispersion

Preparation and properties of rosin-based cationic waterborne polyurethane dispersion

Investigating Physio-Thermo-Mechanical Properties of Polyurethane and Thermoplastics Nanocomposite in Various Applications.

The effect of the soft and hard polyurethane (PU) segments caused by the hydrogen link in phase-separation kinetics was studied to investigate the morphological annealing of PU and thermoplastic polyurethane (TPU). The significance of the segmented PUs is to achieve enough stability for further applications in biomedical and environmental fields. In addition, other research focuses on widening the plastic features and adjusting the PU–polyimide ratio to create elastomer of the poly(urethane-imide). Regarding TPU- and PU-nanocomposite, numerous studies investigated the incorporation of inorganic nanofillers such as carbon or clay to incorporating TPU-nanocomposite in several applications. Additionally, the complete exfoliation was observed up to 5% and 3% of TPU–clay modified with 12 amino lauric acid and benzidine, respectively. PU-nanocomposite of 5 wt.% Cloisite®30B showed an increase in modulus and tensile strength by 110% and 160%, respectively. However, the nanocomposite PU-0.5 wt.% Carbone Nanotubes (CNTs) show an increase in the tensile modulus by 30% to 90% for blown and flat films, respectively. Coating PU influences stress-strain behavior because of the interaction between the soft segment and physical crosslinkers. The thermophysical properties of the TPU matrix have shown two glass transition temperatures (Tg’s) corresponding to the soft and the hard segment. Adding a small amount of tethered clay shifts Tg for both segments by 44 °C and 13 °C, respectively, while adding clay from 1 to 5 wt.% results in increasing the thermal stability of TPU composite from 12 to 34 °C, respectively. The differential scanning calorimetry (DSC) was used to investigate the phase structure of PU dispersion, showing an increase in thermal stability, solubility, and flexibility. Regarding the electrical properties, the maximum piezoresistivity (10 S/m) of 7.4 wt.% MWCNT was enhanced by 92.92%. The chemical structure of the PU–CNT composite has shown a degree of agglomeration under disruption of the sp2 carbon structure. However, with extended graphene loading to 5.7 wt.%, piezoresistivity could hit 10−1 S/m, less than 100 times that of PU. In addition to electrical properties, the acoustic behavior of MWCNT (0.35 wt.%)/SiO2 (0.2 wt.%)/PU has shown sound absorption of 80 dB compared to the PU foam sample. Other nanofillers, such as SiO2, TiO2, ZnO, Al2O3, were studied showing an improvement in the thermal stability of the polymer and enhancing scratch and abrasion resistance.

Synthesis, characterization and dispersion stabilities of novel ionic and nonionic diol modified waterborne polyurethane dispersions with different polyols

Several high solid content waterborne polyurethane dispersions (WPUDs) with the combination of anionic and nonionic stabilization were synthesized by polyaddition reaction using isophorone diisocyanate (IPDI), trimethylol propane (TMP) and 1,6-hexanediol (HDO) as the hard segments, polypropylene glycol with molecular weight of 2000 Da (PPG-2000), and polytetramethylene ether glycol with molecular weight of 2000 Da (PTMG-2000) as the soft segments, anionic diol dimethylol propionic acid (DMPA) and nonionic diol Y-mer N 120 (NID) as the donors of hydrophilic groups. The chain extension reaction between residual NCO groups was made by using hydrazine (HYD). The effects of the combination of anionic and nonionic monomer and macrodiol types on the performance of the WPUDs were studied in terms of particle size distribution and dispersion stability. The results showed that the WPUDs exhibited narrow particle size distribution, good appearance and good mechanical properties.

Recent developments in waterborne polyurethane dispersions (WPUDs): a mini-review on thermal and mechanical properties improvement

Recent developments in waterborne polyurethane dispersions (WPUDs): a mini-review on thermal and mechanical properties improvement

Photothermal Waterborne Polydopamine/Polyurethanes with Light-to-Heat Conversion Properties

A polydopamine-polyurethane (PDA-WPU)-based polymeric matrix with efficient light-to-heat conversion properties that can initiate light-activated temperature elevations is presented. The polymerization of dopamine monomer in a pre-synthesized aqueous polyurethane dispersion resulted in hybrid polyurethane-polydopamine particles via the coating of discrete waterborne polyurethane (WPU) particles with photothermal polydopamine. The resulting polydopamine-polyurethane (PDA-WPU) dispersions presented a unimodal particle-size distribution and particle sizes that increased as a function of the initial dopamine concentration and polymerization time. Films cast from PDA-WPU dispersions were black-colored and presented a homogeneous morphology with contact angles that decreased with increasing PDA content. While the thermal decomposition behavior and thermal conductivity values of hybrid PDA-WPU films were improved relative to neat WPU films, the glass transition temperatures remained unaffected and the films presented acceptable mechanical properties. PDA-WPU films prepared with the highest amount of polydopamine reached 105.8 °C when irradiated with solar light at 3 sun for 20 min. Five min of irradiation with NIR laser light at 800 mW/cm2 elevated the temperatures of the PDA-WPU films from room temperature to 138.6 °C. Moreover, PDA-WPU dispersions were molded in the form of a container to investigate their potential in solar-driven water-evaporation applications. The hybrid PDA-WPU polymer matrix prepared via a facile postsynthesis modification of WPU dispersions with polydopamine synergistically possesses the features of both components and presents strong photothermal activity along with its easy-to-apply, nanoparticle-free, and environmentally friendly nature; thus, this matrix can be viewed as a promising candidate for a wide range of photo-driven applications.

Comparative Life Cycle Assessment of Different Production Processes for Waterborne Polyurethane Dispersions

This study provides a comparative life cycle assessment (LCA) of four different polyurethane dispersion production processes from cradle-to-gate. The environmental performances of the NMP process, the acetone process, the melt process, and a conceptualized continuous flow process were evaluated and compared following the CML 2001 methodology. The LCA revealed that the conceptualized flow process exhibits the lowest environmental impact in all investigated impact categories. Depending on the impact category, the melt process or the acetone process rank second. The NMP process was observed to have the highest impact in all categories. Consequently, the flow process has the lowest carbon footprint (1.13 kg CO2-eq), according to the global warming potential (100 years), followed by the melt (1.45 kg CO2-eq), the acetone (1.95 kg CO2-eq) and the NMP process (3.11 kg CO2-eq).

Highly absorbent hydrogels comprised from interpenetrated networks of alginate\u2013polyurethane for biomedical applications

Developing new approaches to improve the swelling, degradation rate, and mechanical properties of alginate hydrogels without compromising their biocompatibility for biomedical applications represents a potential area of research. In this work, the generation of interpenetrated networks (IPN) comprised from alginate–polyurethane in an aqueous medium is proposed to design hydrogels with tailored properties for biomedical applications. Aqueous polyurethane (PU) dispersions can crosslink and interpenetrate alginate chains, forming amide bonds that allow the structure and water absorption capacity of these novel hydrogels to be regulated. In this sense, this work focuses on studying the relation of the PU concentration on the properties of these hydrogels. The results indicate that the crosslinking of the alginate with PU generates IPN hydrogels with a crystalline structure characterized by a homogeneous smooth surface with high capacity to absorb water, tailoring the degradation rate, thermal decomposition, and storage module, not altering the native biocompatibility of alginate, providing character to inhibit the growth of E. coli and increasing also its hemocompatibility. The IPN hydrogels that include 20 wt.% of PU exhibit a reticulation index of 46 ± 4%, swelling capacity of 545 ± 13% at 7 days of incubation at physiological pH, resistance to both acidic and neutral hydrolytic degradation, mechanical improvement of 91 ± 1%, and no cytotoxicity for monocytes and fibroblasts growing for up to 72 h of incubation. These results indicate that these novel hydrogels can be used for successful biomedical applications in the design of wound healing dressings.

Soybean-based polymers and composites

Abstract Development and evaluation of new bio-based sustainable plastics to replace the petroleum-based materials in different industrial applications has both environmental and economic benefits. Bio-based polymers can be widely used in biomedical and agriculture applications due to their excellent biodegradability and biocompatibility. Soy protein is a natural material that can be isolated from soybean, which is a major agricultural crop in the U.S. The viability of soybean-based polymers and composites is questioned due to their high-water absorption and poor mechanical properties. There have been many environmentally friendly attempts to improve the properties of soybean polymers as soybeans and their extracts are widely available worldwide. Soy protein, hulls, and oils all find use in the development of different biodegradable polymers. While the development looks promising, there is still more work to do to make the soybean polymers useful and economically viable. Blending soy protein with other biodegradable polymers, such as polylactide (PLA) and polyurethane dispersion is a valid approach to improve the mechanical properties of soy protein and reduce its water sensitivity.

Preparation and Properties of Biobased, Cationic, Waterborne Polyurethanes Dispersions from Castor Oil and Poly (Caprolactone) Diol

Biobased cationic waterborne polyurethanes (WPUs) were prepared using isophorone diisocyanate (IPDI), N-methyl diethanolamine (N-MDEA), polycaprolactone (PCL) diol, hydrochlotic acid (HCl), and 1,4-butanediol (BDO). To improve the mechanical performance and adhesive strength of the waterborne polyurethane films, different amounts of castor oil (CO) acting as a cross-linking agent were incorporated in the polyurethane structure. The structures of the waterborne polyurethanes were assessed by Fourier-transform infrared spectroscopy (FTIR). The combination of CO had a positive effect on the dispersion and stability properties of WPUs. WPUs containing higher content of CO demonstrated a remarkable enhancement in homogeneity among particles. The stable aqueous dispersion was obtained even when N-MDEA loading was as low as 3.2 wt%; a bonus of this low hydrophilic moiety was the excellent adhesive strength, whose T-peel strength could reach up to 36.8 N/25 mm, about 114% higher than that of WPU (17.2 N/25 mm) without any CO content. The elongation at break of CO7.40%-WPU was 391%. In addition, the fracture mechanism of the waterborne polyurethane films transformed from the brittle failure to the ductile fracture. The experiment results showed the CO-modified WPUs displayed excellent film-forming property, flexibility, and adhesion, which can be employed for constructing the eco-friendly, biodegradable, cationic, waterborne polyurethanes.

Castor oil-glycerol-based waterborne polyurethane dispersions

In this study, the castor oil-glycerol-based waterborne polyurethane was successfully synthesized. The molar ratio (the ratio between Gly and total polyols) of Gly was up to 50 % and the effects of Gly on the particle size, stability of dispersion, thermal and mechanical properties, surface wettability of the resulting WPU also has been extensively investigated. Notably, the introduction of Gly has extensively improved the tensile strength, Tg, toughness, Young’s modulus, and pencil hardness. The tensile strength could reach up to 30 MPa and Young’s modulus to 333 MPa with elongation at break over 26 %, Tg to 82 °C, pencil hardness to 6H. However, the surface wettability and ve of the resulting materials increases firstly and then decreases, and exhibit maximum water contact angle of 86.8° for 30 % Gly and maximum ve of 389 mol/m3 for 40 % Gly. This work demonstrates that the introduction of Gly not only can increase the bio-content but also effectively improve the performances of WPU, and this work provides an interesting idea for the preparation of high-performance bio-based WPU.

Bio-based polyurethane aqueous dispersions

Abstract With the advances of green chemistry and nanoscience, the synthesis of green, homogenous bio-based waterborne polyurethane (WPU) dispersions with high performance have gained great attention. The presented chapter deals with the recent synthesis of waterborne polyurethane with the biomass, especially the vegetable oils including castor oil, soybean oil, sunflower oil, linseed oil, jatropha oil, and palm oil, etc. Meanwhile, the other biomasses, such as cellulose, starch, lignin, chitosan, etc., have also been illustrated with the significant application in preparing polyurethane dispersions. The idea was to highlight the main vegetable oil-based polyols, and the isocyanate, diols as chain extenders, which have supplied a class of raw materials in WPU. The conversion of biomasses into active chemical agents, which can be used in synthesis of WPU, has been discussed in detail. The main mechanisms and methods are also presented. It is suggested that the epoxide ring opening method is still the main route to transform vegetable oils to polyols. Furthermore, the nonisocyanate WPU may be one of the main trends for development of WPU using biomasses, especially the abundant vegetable oils.

Polyurethane Impregnation for Improving the Mechanical and the Water Resistance of Polypropylene-Based Textiles.

Commercial waterborne polyurethane (PU) dispersions, different in chemistry and selected on the basis of eco-friendly components, have been applied to a common polypropylene (PP)-based woven fabric. Impregnation has been chosen as a textile treatment for improving the features of basic technical textiles in light of potential applicability in luggage and bag production. The effect of drying method, performed under conditions achieved by varying the process temperature and pressure, on the features of the treated textiles, has been verified. The prepared specimens were characterized in terms of mechanical behavior (tensile, tear and abrasion resistance) and water resistance (surface wettability and hydrostatic pressure throughout the treated textiles). The experimental results suggest an incremental improvement of the tensile features for all the investigated specimens. For tear strength, no augmentation compared to that of the neat textile, could be verified as a consequence of polyurethane treatment. Remarkable improvements of abrasion resistance were displayed for all the impregnated PP textiles. Benefits in water resistance could be attributed to the presence of hydrophobic PU in the textile weaving of the PP samples. The ultimate improvement in water resistance was dependent on drying conditions.

Development of coalescents for paints and varnishes based on ionic liquids – the products of diethanolamine and inorganic acids interaction

This paper reports the synthesis of ionic liquids through the interaction between diethanolamine and orthophosphate and boric acids in order to establish the possibility of replacing volatile coalescents in a formulation for paints and varnishes with ionogenic compounds. The results from studying the influence of polymeric coalescents based on ionic liquids on the rheological properties of water-dispersion paints and varnishes of different nature are presented. It has been established that the synthesized coalescents could be used to modify the properties of paints and varnishes based on polyurethane and styrene-acrylic aqueous dispersions. It has been shown that the product of the interaction between diethanolamine and boric acid in aqueous solutions forms an ionogenic complex compound with a unipolar conductivity in terms of ОН─ ions. It was also established that when introduced to the formulation of water-dispersion paints and varnishes, the solutions of modifiers produce a diluting action. The influence of ionic liquids on the process of film formation of aqueous dispersions of polymers and pigmented paints and varnishes based on them was investigated. It was established that the synthesized ionogenic compounds are not inferior, in terms of their effectiveness, to the widespread conventional industrial coalescents of the Texanol→ type. Therefore, there is reason to assert the possibility of replacing the industrial coalescent Texanol→ in the formulation of pigmented water-dispersion paints and varnishes based on styrene-acrylic and polyurethane dispersions with fundamentally new synthesized ionogenic modifiers. Thus, the coatings with a coalescent based on ion liquid of diethanolamine borate have a higher level of conditional hardness, which exceeds by 17 % the hardness index of the paint made on the basis of the conventional Texanol→ type coalescent, without changing its decorative properties, such as color and shine

Development of flame-retardant waterborne polyurethane dispersions (WPUDs) from sulfonated phosphorus-based reactive water-dispersible agents

The current study presents an attempt to develop two molecules, namely sulfonated aromatic diol (SAD) and sulfonated aromatic diamine (SADAM), to induce flame retardancy, thermal stability, and dispersion ability for water-based polyurethane dispersions (WPUDs). The previously reported itaconic acid-based polyester polyol was used for prepolymer synthesis as well as for chain extension. Pre- and post-sulfonated compounds were subjected to characterization tests such as FTIR, 13C-NMR, 1H-NMR, and CHNS for confirmation of their structures. The standard dispersant used for the basis of comparison was commercially available dimethyl propionic acid (DMPA). WPUDs were synthesized in different molar concentrations of DMPA, SAD, and SADAM, and the covalent incorporation of all three molecules in the polymer backbone was confirmed by FTIR. The WPUD films were subjected to various thermal tests like TGA and DSC as well as mechanical tests like flexibility and pencil hardness. WPUD films obtained from SADAM showed a remarkable increase in Tg as well as char content. The THRI values for SAD- and SADAM-based films were better than DMPA-based films. SAD- and SADAM-based WPUD films also showed an increase in LOI value and UL-94 ratings with the maximum LOI value of 26. Dispersions based on DMPA showed better stability as compared to dispersions based on SAD and SADAM.

Chemical and Thermo-Mechanical Properties of Waterborne Polyurethane Dispersion Derived from Jatropha Oil.

Nowadays, there is a significant trend away from solvent-based polyurethane systems towards waterborne polyurethane dispersions due to government regulations requiring manufacturers to lower total volatile organic compounds, as well as consumer preference for more environmentally friendly products. In this work, a renewable vegetable oil-based polyol derived from jatropha oil was polymerized with isophorone diisocyanate and dimethylol propionic acid to produce anionic waterborne polyurethane dispersion. Free standing films with up to 62 wt.% bio-based content were successfully produced after evaporation of water from the jatropha oil-based waterborne polyurethane (JPU) dispersion, which indicated good film formation. The chemical and thermo-mechanical properties of the JPU films were characterized. By increasing the OH numbers of polyol from 161 mgKOH/g to 217 mgKOH/g, the crosslinking density of the JPU was significantly increased, which lead to a better storage modulus and improved hydrophobicity. Overall, JPU produced from polyol having OH number of 217 mgKOH/g appears to be a promising product for application as a binder for wood and decorative coatings.